Monopolar and bipolar electrode for a urological resectoscope

ABSTRACT

The invention relates to an electrode which can be subjected to a high frequency, comprising an electrode carrier having at least one external, insulated conductive wire. Said electrode is used in a urological resectoscope having an axially extending shaft tube, the proximal end thereof being fixed to a main body. A sliding body is proximally positioned in relation to the main body, and can slide in a parallel manner in relation to the axis thereof. Said sliding body comprises a receiver into which the proximal end region of the electrode carrier can be introduced—said carrier penetrating the main body and being positioned in such a way that it can slide axially in the shaft tube assembly position—in order to fix a fixing section of the electrode carrier by means of a fixing device pertaining to the sliding body, and in order to contact a first contacting section of the electrode carrier by means of a first contacting device pertaining to the main body. The inventive electrode is characterized in that the fixing section is proximally arranged in relation to the first contacting section.

[0001] The present invention relates to a monopolar and to a bipolarelectrode for a urological resectoscope of the kind defined in thepreambles of claims 1 and 2 resp.

[0002] Resectoscopes of this kind are used foremost for prostateresections, though, depending on the particular design, they also may beused for other surgical purposes. Herein the concept of Aresectoscope@denotes endoscopic instruments wherein an optics and a monopolar orbipolar electrode-support together with one or two distal electrodes,for instance a resecting and a neutral electrode configured in a stemtube, the electrode support jointly with the electrodes being configuredin axially displaceable manner and being affixed at its proximal end toa resectoscope slide block with which it makes electric contact, saidslide block being axially displaceable by manually driving a grip inorder to axially displace the said electrode.

[0003] During prostate resection, the resectoscope is advanced by itsdistal stem tube end through the urethra inside the prostrate. When hfis applied to the electrode, this electrode may be advanced andretracted by manually driving the slide block in order to cut tissue. Ingeneral the electrode is configured as a wire loop to trim tissuesnippets. Furthermore the electrode may assume other geometries, forinstance being a button electrode, a roller electrode, a knife electrodeor the like, in order to allow application to different purposes such ascoagulation, cutting or the like.

[0004] Classical resectoscopy makes use of the monopolar, i.e. unipolartechnology. Therein an hf current is set up between the resectionelectrode—the active electrode—through the patient's body and a neutralelectrode of comparatively large surface externally affixed to thepatient, for instance to his thigh.

[0005] However the electric current through the patient's body entailsrisks which cannot be totally excluded even when the resectoscope ishandled expertly. For instance there are uncontrollable leakage or driftcurrents which, if the patient were to touch a metal, for instance thatof the operational table, may result in painful skin burns. Also, asregards current-induced muscle contractions, there is the danger thepatient may move suddenly in uncontrolled manner whereby he might be cutby the resectoscope. There is always some danger that muscles or nervesin the vicinity of the resection zone shall be damaged at leasttemporarily drifting currents.

[0006] The above cited risks may be nearly entirely eliminated whenusing bipolar techniques. All such techniques offer the feature that notonly the active electrode, but also the neutral, ie return electrode,are inserted into the body of the patient, as a result of which the hfcurrent is set up only between the two electrodes at the electrodesupport—but not, or merely over defined, short paths, through the bodyof the patient. Such a bipolar electrode is disclosed in the GermanOffenlegungsschrift 25 21 719, wherein therefore the electrode supportis crossed by two electrical conductor wires.

[0007] Alternatively it is known with respect to bipolar electrodes toreplace the neutral electrode with a second active electrode acting asthe return electrode, the electric current being set up between thesetwo electrodes each of which makes contact with the tissue. Such abipolar electrode is shown in the patent document WO 96/234449.

[0008] However both the monopolar and bipolar electrodes incur theproblem of properly setting up electrical contact between the conductorwires feeding an electric current to the electrodes and their contactzones in the slide block. There the electrical connection, i.e. thecontact, must be set up using extension cables leading to the outputterminals of a separately set up hf generator. HF-loaded contact sitesare problematical and tend to defects such as charring.

[0009] In older designs, a tightening screw simultaneously sets up thecontact and the mechanical affixation of the electrode support insidethe slide block. Once such a contact site shall char, the full slideblock shall have to be replaced.

[0010] A monopolar design of this kind is known from each FIG. 3 in U.S.Pat. Nos. 4,917,621 and 4,919,131. The slide block is fitted with acontinuous transverse cavity accepting the plug of the hf extensioncable to contact the bared contact zone of the electrode support in thiscavity. A clamping element acting on the affixation zone of theelectrode support is configured distally relative to the cavity.

[0011] This design offers the advantage of separately mechanicallyaffixing the electrode support and the clamping element on the slideblock, as a result of which it is possible to first check this slideblock's appropriate mechanical operation. Thereupon contact may beimplemented with the plug. If the contact site should char, only theelectrode support and the cable together with the plug need be changed.The clamping element and the slide block on the other hand remain intactbecause the clamping element is separate.

[0012] However the known design of the above species does entaildrawbacks. Because the affixation device is configured distally from thecontacting element, the electrode support site where affixation takesplace is crossed by the electric conductor connecting the contactingsite to the active electrode. As a result the electrode support lacksmechanical strength in this region. The affixation device must allow forthis lack of strength and illustratively may only operate with minutetightening forces. If affixation takes place by means of a slide blockentering a groove and acting on the electrode support, then said groovemay only be very shallow and consequently the reliability of affixationshall be considerably reduced.

[0013] The proximal end zone of the electrode support is constitutedboth by that zone wherein affixation takes place and by the contactingzone. These zones, namely the full end zone of the electrode support,therefore are rigid and more resistant to bending than the remainder ofthe electrode support which consists only of an inner conductor and anouter insulation. In resectoscopes, however, the electrode supporttypically will be configured tightly against the optics inside the stemtube, whereas, in the region of the slide block, said support and saidoptics must be farther apart in order to subtend enough space for thecontacting system and the affixation device. Therefore the electrodesupport must be pivotably supported inside the main block in the mannerindicated for instance in FIG. 13 of the patent document WO 96/234449.However the main block being required to be of moderate length ontechnical grounds, substantial pivoting must take place over a shortpath. But such a motion is hampered by the considerable length of therigid end region of the known electrode supports.

[0014] Moreover assembly may be defective if the electrode support wasinsufficiently inserted and thereupon was fixed in place and contacted.

[0015] As regards the FIG. 16 of the patent document WO 96/234449 of thepresent species, which includes a bipolar electrode, the electrodesupport is fitted with two contact zones in the region of the slideblock. An extension cable plug which can be affixed to the slide blocksets up contact with both contact zones which it furthermore clampsonto. This design does not provide a separate, special affixationelement. Therefore this design precludes affixing the electrode supportto test mechanical operation before contacting takes place.

[0016] The objective of the present invention is to create an improved,monopolar or bipolar electrode of the above species, allowing to affixthe electrode support in the slide block and to set up an electricalconnection, i.e. contact, with both steps being implemented inproblem-free manner.

[0017] This goal is attained by the features of claim 1.

[0018] In this invention, the electrode support of the electrode isseparate from the affixation zone and is configured proximally relativeto the first contact zone. Accordingly as regards the resectoscope'sslide block, the affixation element must be proximal relative to thefirst contact element.

[0019] As a result of this design separation, the electrode support onone hand must be mechanically separately affixed by means of theaffixation element on the slide block whereby its appropriate mechanicaloperation may be tested in a first step. Thereupon a plug may be appliedto set up electrical contact. If the contact zone should char, then onlythe electrode support jointly with the cable and plug need be exchanged.The clamping element and the slide block remain intact because theformer is now designed separately. This electrode design moreover offersthe advantage that the affixation zone of the electrode support nolonger is crossed by an inner conductor and consequently may be designedfor high mechanical strength. A number of different highly reliableaffixation methods may be used, for instance clamping by applying highclamping forces, locking into deep grooves or even locking by means of apin through a transverse borehole in the electrode support. Furthermorehighly retentive snap-in connections may be used. Another advantageoffered by the proximal configuration of the affixation zone is that,assuming proper affixation, the electrode support shall be entirelyinserted, that is, the electrode support's contact zone shall beconfigured at the site of the contact element and hence electricalcontacting can be set up. Lastly the problem of pivoting the rigid endzone of the electrode support during insertion into the main block maybe very effectively solved. The bending-resistant end piece consistingof the contact zone and the affixation zone may be shortened. Theelectrode support's affixation zone also may be designed with a lesserdiameter, thereby enabling tighter pivoting.

[0020] Claim 2 advantageously proposes with respect to a bipolarelectrode that the affixation zone shall be configured apart from bothcontact zones and proximally to at least one of them. In this manner itis possible to first test its appropriate mechanical operation beforesetting up electrical contact by means of a plug.

[0021] The electrode features of claim 2 on one hand make it possible toconfigure the first contact zone proximally and to mount the second onedistally from the affixation zone. In corresponding manner theaffixation element should be configured between the two contact elementsin the slide block. Advantageously only one inner conductor would crossthe affixation zone and thereby a higher clamping force might be appliedto the affixation zone. This feature also would facilitate insulatingthe two contact zones because they already are being separated by theaffixation zone when latter is made of an insulating materials such as anon-conducting ceramic.

[0022] However the features of claim 3 are proposed in advantageousmanner. Thereby the two contact zones shall be configured distallyrelative to the affixation zone. In this case and with respect to theresectoscope's slide block, the affixation element also shall beproximal relative to the two contact devices. Such an electrode designoffers the advantage in the first place that neither inner conductorshall cross the electrode support's affixation zone and thereby saidzone may be designed for very high mechanical strength. In this mannerthe affixation advantages cited in claim 1 in relation to a monopolarelectrode are attained here too. Another advantage offered by theaffixation zone's proximal configuration is that, assuming properaffixation procedure, the electrode support shall be reliably fullyinserted and therefore that the electrode support's contact zones alsoshall be situated at the sites of the contact elements, wherebycontacting free of defects may take place. Lastly, and in this instanceagain, the problem encountered with pivoting the stiff end segment ofthe electrode support during insertion through the main block can bevery effectively solved. The bending-resistant end piece consisting ofthe two contact zones and of the affixation zone then may be shortened,however the insulation between the two contact zones must be preserved.The electrode support's affixation zone also may be designed to be of alesser diameter, as a result of which guidance by a tighter pivotingmotion shall be improved.

[0023] The features of claim 4 are advantageous. Such a design is madepossible for the first time by means of this invention whereby theaffixation zone is wholly separated from the remaining design of theelectrode support in order to attain good affixation. A solid andcontinuous metal design may be selected in accordance with claim 5.

[0024] According to claim 6, the affixation zone and at least part of anadjacent contact zone may be integral. As a result the design issimplified with respect to manufacture and greater mechanical strengthis attained. When both contact zones are situated distally from theaffixation zone, then, according to the invention, at least the proximalpart of the contact zone adjacent to the affixation zone shall be madeintegral with the affixation zone. When the affixation zone is situatedbetween the two contact zones, then selectively either the distalportion of the contact zone proximally adjacent to the affixation zoneshall be integral with the affixation zone, or at least the proximalportion of the contact zone which is distally adjacent to the affixationzone shall be integral with the affixation zone.

[0025] Claim 7 advantageously proposes that the affixation zone shall bemade of an electrically insulating material if it is configured betweenthe two contact zones. In that case the affixation zone contributes toinsulated length and thereby allows shortening the electrode's proximalend.

[0026] The invention is shown in illustrative and schematic manner inthe drawings.

[0027]FIG. 1 is an axial section of a resectoscope and shows a firstillustrative embodiment of an assembled monopolar electrode,

[0028]FIG. 2 is an axial section of the proximal end of a resectoscopeand shows a first illustrative embodiment of an assembled bipolarelectrode, and

[0029]FIG. 3 is an axial section of the proximal end of a resectoscopeand shows a second illustrative embodiment of an assembled bipolarelectrode.

[0030] The resectoscope 1 shown in FIG. 1 comprises a stem tube 2 whichis affixed by its proximal end to a main block 3. In manner not shown,the stem tube 2 may be detachably mounted by means of a conventionalcoupling to the main block 3. An external tube 4 encloses the stem tube2 and also is affixed to the main block 3, again in conventional mannerand by means of an omitted coupling. The inside of the stem tube 2serves as feed duct for permanent irrigation and, as shown by FIG. 1, isaccessible externally through a valve-fitted hookup 5 which may beconnected to a hose. Another identical hookup 6 to connect another hoseis connected to the annular gap between the stem tube 2 and the externaltube 4 acting as the return duct.

[0031] The two tubes 2 and 4 are conventionally metallic. The distal endzone of the stem tube 2 is conventionally insulating and illustrativelyin the form of a ceramic element 7.

[0032] An optics 8 runs axially inside the stem tube 2 and, in the shownassembled configuration, views by its distal objective 9 the field ofsurgery ahead of the ceramic end element 7, while proximally it runsthrough the main block 3. From the latter position it runs through aguide tube 10 affixed in the main block 3 and terminates on the otherside of the proximal end of said tube 10 into an ocular 11 that may bereplaced by a camera.

[0033] By means of a guide borehole 12, a slide block 13 rests inaxially displaceable manner on the guide tube 10. An end plate 14 isaffixed to the proximal end of the guide tube 10 and by means of aconventional leaf spring 15 resiliently braces the slide block 13. Athumb ring 16 is mounted on the end plate 14, and a finger grip 17 ismounted on the slide block 13. Using one hand, the surgeon by means ofthe thumb and index finger can actuate resp. the thumb ring 16 and thefinger grip 17 and thus may axially displace the slide block 13.Alternatively the just discussed Aactive@ function may be replaced by aApassive@ function wherein the leaf spring 15 is configured between theslide block 13 and the main block 3 and the drive sites 16, 17 also aresituated at these components.

[0034] The shown resectoscope includes an exchangeable, hf-loaded,monopolar electrode 18 which is of conventional design with respect toprostate resection, namely it is in the form of a wire loop of which theplane is orthogonal to the axial direction. The electrode 18 issupported by an electrode support 19 in the form of an inner conductingwire 20 enclosed by an external insulation. In conventional manner, thiselectrode support 19 rests by means of a sleeve 21 in longitudinallydisplaceable manner on the optics 8 and runs through the stem tube 2 asfar as the main block 3. From there it runs through a laterally deviatedtransmission duct 22 fitted with O rings 23 or the like to seal off theliquids, next running from said duct's proximal mouth again parallel tothe axis but at a larger distance from it into a seating borehole 24 inthe slide block 13. In an alternative embodiment, the seating borehole24 may be replaced for instance by a proximally conically convergingaperture, or a sideways open slot, or the like, to seat the electrodesupport 19.

[0035] In its proximal end region, the electrode support 19 comprises anaffixation zone 25 constituting its end element, said end zone 25 beingappropriately mechanically strong, for instance being made of solidmetal in order to allow reliably mechanically affixing the electrodesupport at that site. Distally from there, the electrode support 19adjoins a contact zone 26 fitted with an electrically conducting outsidesurface that is connected in electrically conducting manner with theconducting wire 20 of the electrode support 19.

[0036] In the form of its proximal end 27, the seating borehole 24further comprises a limit stop for the electrode support 19 which can beinserted in the proximal direction into said seating borehole 24 as faras said stop.

[0037] When, in the shown assembly, the electrode support 19 has beeninserted in the seating borehole 24 of the slide block 13 as far as thelimit stop 27, then it shall be situated with its contact zone 26 in aclearance 28 of the slide block 13 wherein said contact zone 26 isfreely accessible from the outside. In that configuration, saidelectrode support 19 may be electrically contacted for instance by theshown clamping plug 29 at the end of a cable 30 running to an omitted hfgenerator.

[0038] An affixation element, which in this embodiment comprises atransverse borehole 31, is configured directly proximally next to theclearance 28 in the region of the affixation zone 25 of the electrodesupport 19 in the slide block 13 and illustratively is fitted with aninside thread to allow screwing-in a tightening screw. Alternatively theaffixation element also may be of another design, for instance includinga slider engaging a groove, or in the form of a snap-in connection orthe like.

[0039] As shown, the clearance 28 may offer omnidirectional, free accessto the contact zone 26 of the electrode support 19, however, and inillustrative manner, it may also be designed as a cavity accessible onlyfrom one side as disclosed for instance in U.S. Pat. No. 4,919,131.

[0040] Once the electrode support 19 shall be appropriately affixed inthe slide block 13 and make appropriate electrical contact, then, bymeans of the above displacement of the slide block 13, the entireelectrode support 19 together with the electrode 18 may be displacedlongitudinally relative to the stem tube 2. Thereupon, by observationthrough the optics 8 and applying hf to the electrodes 18 and 118, saidelectrode may be used for cutting while moving axially.

[0041] The clamping plug 29 will be removed and the affixation element(transverse borehole 31) will be loosened when the electrode support 19must be exchanged. Thereupon the electrode support may be fullyextracted in the distal direction from the resectoscope 1. Reversely, anew electrode may be inserted in the proximal direction as far as thelimit stop 27, then be mechanically affixed and electrically contacted.The electrode support 19 may be first mechanically affixed to thetransverse borehole 31 and its appropriate mechanical operation may betested by displacing to and fro the slide block 13 before electriccontacting shall be implemented with the clamping plug 29.

[0042]FIGS. 2 and 3 show two mutually alternative bipolar electrodes ofthe invention in their assembled state, identical elements as in FIG. 1being denoted here identically too. Examples of representative bipolarelectrodes are disclosed in the German patent document 100 28 850.2 andin the documents cited therein. Therefore the distal regions of thebipolar electrodes are not shown in FIGS. 2 and 3.

[0043]FIG. 2 shows two electrically conducting wires 20 and 120 insidethe insulating electrode support 119 and running distally as far as theactive and the return electrodes and connecting said electrodes inelectrically conducting manner with a first and a second contact zone 26and 126 which are just as much insulated from each other as are theconducting wires 20 and 120 and which may be connected for instanceusing a double plug. Similarly to the embodiment shown herein, it isalso possible to conductively connect the return electrode with thefirst contact zone and the active electrode with the second contactzone.

[0044] The electrode support 119 comprises an affixation zone 25 betweenthe two contact zones 26 and 126, said affixation zone being designed tobe mechanically strong enough to reliably mechanically affix theelectrode support 119 at said affixation zone 25. Illustratively theaffixation zone 25 may consist of an insulating material of adequatemechanical strength. As before, the electrode support 119 comprises anearby first contact zone 26 which is fitted with an electricallyconducting outside surface that in turn is connected in electricallyconducting manner with the conductor wire 20 of the electrode support119.

[0045] The electrode support 119 furthermore is fitted proximally fromthe affixation zone 25 with a second contact zone 126 which alsocomprises an electrically conducting outside surface that in turn isconnected in electrically conducting manner with the second conductorwire 120 of the electrode support 119.

[0046] In the manner already shown in relation to FIG. 1, the seatingborehole 24 by means of its proximal end 27 comprises a limit stop forthe electrode support 119, and said support may be inserted in theproximal direction through the seating borehole 24 as far as said stop.

[0047] If, in the shown assembly configuration, the electrode support119 was inserted as far as the limit stop 27 into the seating borehole24 of the slide block 13, then it shall be situated by its contact zone26 in a clearance 28 in the slide block 13 where the contact zone 26 isfreely accessible from the outside. At the same time said electrodesupport is situated by its contact zone 126 in a second clearance 128 ofthe slide block 13 where this second contact zone 126 is freelyexternally accessible. Both said contact zones may be electricallyconnected at said sites, for instance by means of the shown clampingplugs 29 and 129, to the ends of cables 30 and 130 leading to the outputof an omitted hf generator. Such electrical connection, i.e. contacting,also may be implemented using a double plug which simultaneouslyimplements electrical connection to the two contact zones 26 and 126.

[0048] Lastly FIG. 3 shows a second and exchangeable hf-loaded bipolarelectrode support 219 in the form of inner conductor wires 20 and 120enclosed by an insulation. The electrode support 219 at its proximal endcomprises an affixation zone 25 constituting its end piece and beingsufficiently strong mechanically, for instance being of solid metal, toreliably mechanically secure the electrode support 19 in that place.Distally adjoining it, the electrode support 219 comprises, as before, afirst contact zone 26 fitted with an electrically conducting outsidesurface which is connected in electrically conducting manner with theconductor wire 20 of the electrode support 219. A second contact zone126 follows distally away from the first contact zone 26 and isinsulated from it and also is fitted with an electrically conductingoutside surface which in turn is connected in electrically conductingmanner with the conductor wire 120 of the electrode support 219.

[0049] When, in the shown assembled configuration, the electrode support219 has been inserted as far as the limit stop 27 in the seatingborehole 24 of the slide block 13, then it shall be situated by itsfirst contact zone 26 in a clearance 28 of the said slide block 13wherein the contact zone 26 is freely accessible from the outside. Atthe same time its second contact zone 126 is situated in a secondclearance 128 of the slide block 13 wherein the contact zone 126 isfreely accessible. Both said contact zones in the clearances 28, 128 maybe electrically connected for instance by means of the shown twoclamping plugs 29 and 129 positioned at the ends of the extension cables30 and 130 resp. which run to the two output terminals of an omitted hfgenerator.

[0050] An affixation element corresponding to that described above inrelation to FIG. 1 is configured in the slide block 13 directlyproximally next to the first clearance 28 in the region of theaffixation zone 25 of the electrode support 219.

[0051] As shown, the clearances 28 and 128 may provide free andomnidirectional access to the contact zones 26 and 126 of the electrodesupport 219, or illustratively they may be configured as cavities whichare accessible only from one side for instance in the manner disclosedin U.S. Pat. No. 4,919,131.

[0052] In order to exchange the electrode support 219, the clampingplugs 29 and 129 are removed and the affixation element (transverseborehole 31) is loosened. Thereupon the electrode support 219 may befully extracted in the distal direction from the resectoscope 1.Reversely a new electrode may be inserted in the proximal direction asfar as the limit stop 27 and be mechanically secured and electricallyconnected by contacting. This design allows first to mechanically securethe electrode support 19 in the transverse borehole 31 and to testappropriate mechanical operation by moving the slide block 13 to-and-frobefore electrical connection is implemented by means of the clampingplugs 29 and 129.

[0053] Instead of the embodiments shown herein, the electrode 18 alsomay assume other geometries, for instance being in the form of a buttonelectrode, a pin electrode, a roller electrode or a knife electrode,which, upon being loaded with hf, shall function in coagulating,vaporizing or cutting manner. In the case of bipolar electrodes, one ofthe electrodes may be designed as the neutral electrode that shall nottouch any tissue, whereas the other electrode shall constitute theactive electrode. Just as well, however both electrodes may touch thetissue and function simultaneously for instance in coagulating andresecting manner.

[0054] In all the above embodiments of FIGS. 1 through 3, the limit stoprelating to the insertion of the electrode support 19, 119 or 219 alwaysis the end 27 of the seating borehole 24. However a limit stop also maybe configured at the affixation element itself, for instance at thetightening screw rotating inside the threaded borehole 31. If forinstance a slider is used as a clamping element and enters a groove inthe affixation zone 25, then an appropriate stop also may be configuredat said slider, said stop cooperating in appropriate manner for instancewith a corresponding stop on the affixation zone 25.

[0055] The above embodiments show that the properly mounted electrodesupport 19, 119 or 219 by means of its contact zones 26 and 126 isconfigured in the slide block 13 in clearances 28 and 128 so as to befreely accessible from the outside in order that, as shown, said contactzones may be electrically contacted using, as shown, plugs 29 or 129inserted from the outside, said plugs optionally also being a doubleplug. However other contact devices also are applicable, such as wherethe contact zone 26 makes an electric connection with a terminal affixedto the slide block 13, for instance inside latter, and an extensioncable running from said block in a manner other than shown. In that casethe clearance 28 may be eliminated. The same considerations apply to thesecond contact zone 126 and the second clearance 128.

[0056] In the above shown embodiments, the affixation zone 25 and thecontact zones 26 and 126 are shown being separate. However one of thecontact zones also may be integral with the affixation zone, forinstance the contact zone 26 in FIGS. 1, 2 and 3 or the contact zone 126in FIG. 2.

[0057] As regards such an integral design of affixation zone and contactzone, the former manifestly shall be at an electrical potential. Thisfeature however fails to be a drawback because the slide block 13generally is made of an insulating material and the affixation element31 also may be very easily designed to be electrically insulatingrelative to the outside.

1. An hf-loaded electrode (18) cooperating with an electrode support(19, 119, 219) consisting of at least one externally insulated electricconductor wire (20, 120) for use in a urological resectoscope (1)comprising a stem tube (2) running in the axial direction and affixed byits proximal end to a main block (3), a slide block (13) being supportedproximally from said main block and in axially displaceable mannerparallel to it and comprising a seat (24) into which—in the saidresectoscope's assembled state—is inserted the proximal end region ofthe electrode support (19, 119, 219) resting and axially displaceable inthe stem tube (2) and crossing the main block (3) in order to affix anaffixation zone (25) of the electrode support (19, 119, 219) by means ofan affixation element (31) of the slide block (13) and to electricallycontact a first contacting zone (26, 126) of the electrode support (19,119, 219) by means of a first contacting element (28, 29, 128, 129) ofthe main block (3), characterized in that the affixation zone (25) isconfigured proximally relative to the first contact zone (26, 126). 2.HF-loaded electrode (18) as claimed in claim 1, characterized in thatthe electrode support (119, 219) comprises two electric conductor wires(20, 120) and two contact zones (26, 126) cooperating with them. 3.Electrode as claimed in claim 2, characterized in that the affixationzone (25) is configured proximally relative to the two contact zones(26, 126).
 4. Electrode as claimed in either of claims 1 and 2,characterized in that the affixation zone (25) deviates from theremaining cross-section of the electrode support (19, 119, 219). 5.Electrode as claimed in either of claims 1 and 2, characterized in thatthe affixation zone (25) consists of solid metal.
 6. Electrode asclaimed in either of claims 1 and 2, characterized in that theaffixation zone (25) and at least a portion of an adjacent contact zone(26, 126) are integral.
 7. Electrode as claimed in claim 2,characterized in that the affixation zone (25) is configured between thecontact zones (26, 126) and consists of an insulating material.